Answer the fоllоwing questiоns аbout the lаyers of the heаrt: A) What is the outermost layer of the heart tissue? B) What is the layer of the heart tissue closest to the inside, where the blood is pumped through? C) What is the function of the pericardial cavity and what does it contain? D) Which heart layer is most electrically active? E) What is the function of (i) conductive cardiomyocytes (pacemaker cells) and (ii) contractile (working) cardiomyocytes